scholarly journals Myosin Binding Protein-C Slow is a Novel Substrate for Protein Kinase A (PKA) and C (PKC) in Skeletal Muscle

2011 ◽  
Vol 10 (10) ◽  
pp. 4547-4555 ◽  
Author(s):  
Maegen A. Ackermann ◽  
Aikaterini Kontrogianni-Konstantopoulos
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Protein C ◽  
Binding Protein ◽  
Myosin Binding Protein ◽  
Myosin Binding Protein C ◽  
Myosin Binding ◽  
Kinase A

scholarly journals Protein kinase A–induced myofilament desensitization to Ca2+ as a result of phosphorylation of cardiac myosin–binding protein C

2010 ◽  
Vol 136 (6) ◽  
pp. 615-627 ◽  
Author(s):  
Peter P. Chen ◽  
Jitandrakumar R. Patel ◽  
Inna N. Rybakova ◽  
Jeffery W. Walker ◽  
Richard L. Moss
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Protein C ◽  
Binding Protein ◽  
Cardiac Myosin ◽  
Cross Bridge ◽  
Myosin Binding Protein ◽  
Myosin Binding Protein C ◽  
Myosin Binding ◽  
Kinase A

In skinned myocardium, cyclic AMP–dependent protein kinase A (PKA)-catalyzed phosphorylation of cardiac myosin–binding protein C (cMyBP-C) and cardiac troponin I (cTnI) is associated with a reduction in the Ca2+ responsiveness of myofilaments and an acceleration in the kinetics of cross-bridge cycling, although the respective contribution of these two proteins remains controversial. To further examine the relative roles that cTnI and cMyBP-C phosphorylation play in altering myocardial function, we determined the Ca2+ sensitivity of force (pCa50) and the activation dependence of the rate of force redevelopment (ktr) in control and PKA-treated mouse myocardium (isolated in the presence of 2,3-butanedione monoxime) expressing: (a) phosphorylatable cTnI and cMyBP-C (wild type [WT]), (b) phosphorylatable cTnI on a cMyBP-C–null background (cMyBP-C−/−), (c) nonphosphorylatable cTnI with serines23/24/43/45 and threonine144 mutated to alanines (cTnIAla5), and (d) nonphosphorylatable cTnI on a cMyBP-C–null background (cTnIAla5/cMyBP-C−/−). Here, PKA treatment decreased pCa50 in WT, cTnIAla5, and cMyBP-C−/− myocardium by 0.13, 0.08, and 0.09 pCa units, respectively, but had no effect in cTnIAla5/cMyBP-C−/− myocardium. In WT and cTnIAla5 myocardium, PKA treatment also increased ktr at submaximal levels of activation; however, PKA treatment did not have an effect on ktr in cMyBP-C−/− or cTnIAla5/cMyBP-C−/− myocardium. In addition, reconstitution of cTnIAla5/cMyBP-C−/− myocardium with recombinant cMyBP-C restored the effects of PKA treatment on pCa50 and ktr reported in cTnIAla5 myocardium. Collectively, these results indicate that the attenuation in myofilament force response to PKA occurs as a result of both cTnI and cMyBP-C phosphorylation, and that the reduction in pCa50 mediated by cMyBP-C phosphorylation most likely arises from an accelerated cross-bridge cycling kinetics partly as a result of an increased rate constant of cross-bridge detachment.

Protein kinase A–induced myofilament desensitization to Ca2+as a result of phosphorylation of cardiac myosin–binding protein C

2010 ◽  
Vol 191 (6) ◽  
pp. i17-i17
Author(s):  
Peter P. Chen ◽  
Jitandrakumar R. Patel ◽  
Inna N. Rybakova ◽  
Jeffery W. Walker ◽  
Richard L. Moss
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Protein C ◽  
Binding Protein ◽  
Cardiac Myosin ◽  
Myosin Binding Protein ◽  
Myosin Binding Protein C ◽  
Myosin Binding ◽  
Kinase A

scholarly journals Molecular Screen Identifies Cardiac Myosin–Binding Protein-C as a Protein Kinase G-Iα Substrate

2015 ◽  
Vol 8 (6) ◽  
pp. 1115-1122 ◽  
Author(s):  
Robrecht Thoonen ◽  
Shewit Giovanni ◽  
Suresh Govindan ◽  
Dong I. Lee ◽  
Guang-Rong Wang ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein C ◽  
Binding Protein ◽  
Protein Kinase G ◽  
Cardiac Myosin ◽  
Myosin Binding Protein ◽  
Myosin Binding Protein C ◽  
Myosin Binding
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